The Clinical Activity Score (CAS) in thyroid eye disease uses which TOTAL score to define 'active' disease requiring immunosuppression?
- A ≥2 out of 7
- B ≥4 out of 10
- C ≥3 out of 7 ✓
- D ≥5 out of 10
Correct answer: C. ≥3 out of 7
Explanation
The Mourits Clinical Activity Score has 7 items (spontaneous orbital pain, gaze-evoked pain, eyelid swelling, eyelid erythema, conjunctival injection, chemosis, caruncle/plical oedema) scored 0 or 1 each. A total score ≥3/7 defines clinically active disease and predicts a good response to immunosuppressive therapy (e.g., IV glucocorticoids). An alternative 10-item extended CAS exists, using ≥4 as the cutoff, but the standard 7-item CAS with ≥3 is most widely tested.
Reference: Khurana Comprehensive Ophthalmology, 7th ed.
High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP
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